Migrate to String::new()

src/data/entities.rs

@@ -133,8 +133,8 @@ impl DeckSettings {
         DeckSettings {
             id: 0.into(),
             name,
-            forward: "".to_string(),
-            backward: "".to_string(),
+            forward: String::new(),
+            backward: String::new(),
             filter: "true".to_string(),
         }
     }